The present invention relates generally to biosynthetic processes and organisms capable of producing organic compounds. More specifically, the invention relates to non-naturally occurring organisms that can produce the commodity chemical 1,3-butanediol.
1,3-butanediol (1,3-BDO) is a four carbon diol traditionally produced from acetylene via its hydration. The resulting acetaldehyde is then converted to 3-hydroxybutyraldehdye which is subsequently reduced to form 1,3-BDO. In more recent years, acetylene has been replaced by the less expensive ethylene as a source of acetaldehyde. 1,3-BDO is commonly used as an organic solvent for food flavoring agents. It is also used as a co-monomer for polyurethane and polyester resins and is widely employed as a hypoglycaemic agent. Optically active 1,3-BDO is a useful starting material for the synthesis of biologically active compounds and liquid crystals. A substantial commercial use of 1,3-butanediol is subsequent dehydration to afford 1,3-butadiene (Ichikawa et al., J. of Molecular Catalysis A-Chemical, 256:106-112 (2006); Ichikawa et al., J. of Molecular Catalysis A-Chemical, 231:181-189 (2005)), a 25 billion lb/yr petrochemical used to manufacture synthetic rubbers (e.g., tires), latex, and resins. The reliance on petroleum based feedstocks for either acetylene or ethylene warrants the development of a renewable feedstock based route to 1,3-butanediol and to butadiene.
Thus, there exists a need to develop microorganisms and methods of their use to produce 1,3-BDO. The present invention satisfies this need and provides related advantages as well.